Home Tech ATX vs EATX: The Definitive Comparison Guide

ATX vs EATX: The Definitive Comparison Guide

PCs can claim to be ATX, EATX, Micro ATX, or Mini ITX amongst others. This is quite confusing to folks that don’t have any idea about what this means. The “ATX vs EATX” debate can even be more confusing.

In this article, I will be explaining what these initials mean. I’ll also be giving out tips on how to choose which form factor you should get based on your personal needs or specs.

What The Specifications Represent

ATX, EATX, Mini ITX, and Micro ATX are form factors of a motherboard. Because a motherboard is in different sized devices, its size too differs based on the device it will fit in. 

These specifications help differentiate the motherboards based on size. You’ll immediately know which one will fit in your device based on the motherboard’s initials.

There are a host of other form factors designed for specific devices but in this article, I’ll be concentrating on the form factors you will likely come across when trying to get a new PC or shopping for a motherboard. 

What The Initials Mean

The initials will immediately tell you what size the motherboard is and you can then infer from that information which device it can fit in.



Stands for Advanced Technology eXtended. This tech has been around for a while now, since the 90s. It is the “standard-sized” motherboard used by just about most normal-sized PCs. 

For folks who are thinking of getting a new PC or motherboard, chances are the ATX is what you’ll need. 

Manufacturers keep trying to build on this tech to create alternatives. The Asus 2019 Prime Utopia is one such example.


Stands for Extended Advanced Technology eXtended. From the name, it implies a little bit more than the ATX. This also reflects in its size resulting in a bigger piece of hardware than the normal ATX. 

What the EATX does is that it adds a little bit of something in terms of performance, stability, and all-around improvement across all the important features of a motherboard. 

Micro ATX

The name already implies something smaller than the normal ATX motherboard and that is exactly what the Micro ATX is. 

Made to fit specific devices, the Micro ATX is still powerful like its bigger counterparts (ATX). The difference in size is just due to the compartment it fits in. 

Mini ITX

Stands for Mini Information Technology eXtended. The Mini ITX is smaller than the Micro ATX. This also is necessary due to the type of device the Mini ITX fits in. 

Does Size Matter In Motherboard Form Factors?

The age-old debate about sizes is also present here in motherboard form factors. 

I’ll be explaining why the sizes differ, what you can expect with the different sizes, and any performance difference using four key headings.


The difference in the size of the motherboards leads to differences in important features like RAM and PCI slots. These key differences are explained below. 

Decrease In Form Factor Size Usually Leads To Decrease In PCI Slots

The main talking point is the increased upgradeability of large form factors or motherboards over their smaller counterparts. 

This is because motherboards are mainly made smaller by removing extension slots. This then impacts on users being able to upgrade their PC later.

Examples of losses in upgrade capabilities are typified by the losses of PCI slots when you change form factors (from a normal ATX to a Micro ATX). 

In normal ATX motherboards, there are usually 6 PCI slots – ( 3x PCI-E x16 & 3x PCI-E x16). This then immediately reduces to just 3 PCI slots in the Micro ATX – ( 1x PCI-E x16 & 2x PCI-E x16).

The loss of the PCI slots will be felt keenly when users are trying to improve system usage by using more graphics, network, capture, or sound cards but cannot because of the more limiting slots of the smaller form factor or motherboard. 

Mini ITX is even much more limited in PCI slots than the Micro ATX form factor. It has only one 1x PCI-E x16 slot. 

EATX motherboards boast at least 4 PCI-E x16 slots (or even more in some cases). This gives it a huge advantage, at least in the slots department, over other form factors. 

Decrease In Form Factor Size Sometimes Leads To Decrease In RAM & USB Slots

The motherboard functionality of RAM & USB slots sometimes takes a hit in some cases of reducing your form factor size. 

This certainly does not happen in every motherboard. Differences in company specs are responsible for the differences in RAM Slots in the same form factor size range. 

For instance, changing from ATX to Micro ATX can lead to changes in the available RAM Slots (from 4 to 2).

Most Mini ITX motherboards usually come with just 2 RAM slots. I have to point out though that a few ones possess 4 slots for RAM. 

Motherboard Form Factors

Case Size:-

The key idea here is that if you get a smaller motherboard, chances are you’ll be getting a smaller PC as a whole. 

If you’ve ever looked inside your computer case, you’d see that the motherboard is just about the major component taking a lot of space. 

An important piece of information to note is that components made for ATX PCs usually don’t fit in smaller cases. So you will have to take note of exactly what you’ll be getting or missing out on especially in cases of folks who are building their PC from scratch. 

For folks who want a media center, servers, or something smaller for purposes that won’t overexert system capabilities, then smaller form factors will help you get exactly the kind of PC you want. 

Sometimes though, a case made for a big form factor can accommodate a smaller form factor or motherboard. It is important to know that this is not what happens across all boards or cases but it only happens in some.

Some ATX cases have been known to fit smaller form factors like the Micro ATX or the Mini ITX form factors. 

If you want increased flexibility, you might want to check the case’s specs to know whether it’ll be able to support other form factors apart from the one it was specially designed to hold.


You will have to do your research to make sure you get the best deal based on your preferred specs and needs but usually, the cheapest motherboards are the Micro ATX form factor kinds. 

There are some (Micro) that are much more expensive but across all motherboards, they are still the best bet for folks not willing to splurge.

The upside is a little bit of cash saved. The downside is that you might still buy bigger form factors later if you want upgraded features. 

That’s why you must know what you want when you’re getting a motherboard. If you know you won’t be needing an upgrade or more slots (RAM, USB, PCIs), then you probably don’t need to shell out more for the other bigger form factors.


It is normal to assume that the smaller motherboards might run slower or faster than bigger motherboards but it does not necessarily work out that way.

A difference in all-around performance might still occur but it is just due to the absence of upgradeable features like PCI slots for cards in smaller motherboards and it only comes up for debate when you take up the extra slots offered by the bigger form factors.

It should however be noted that the smaller you go down from factor sizes, the lesser the overclocking capabilities. It’s also advisable to use bigger form factors for high-end users. 

But the verdict is that smaller motherboards don’t necessarily run slower than bigger motherboards. 


There are differences between the two form factors like size and (RAM & PCI-E) slots, choosing the one to buy depends on the preference of the buyer.

If you’re the type that wants more upgrade features and you don’t really care about the increased size of your PC, you might want to get EATX motherboards.

But if you’re more about portability and you know that the normal upgradeable features of the ATX motherboards are good enough, you can splurge for the normal-sized ATX motherboards. 

In the “ATX vs EATX” debate, there are no winners or losers. Just two different form factors for users with different preferences. 

The differences in price and work rate are usually not a factor due to it being little or of not much consequence. 

You may like to read our guide on Best Budget Motherboard.


Motherboards are very important (understating it) in computers. The sizes matter in terms of features like available RAM, USB, PCI slots, and other details like the price.

You should check out the size of the motherboard before buying a new PC or if you’re building one from scratch. It will tell you whether you can upgrade it much in the future. 

The “ATX vs EATX” comparison was made because they are usually the common choices for people with normal and slightly bigger than normal computers. You should decide based on your needs and probably your computer case.